1. Field of the Invention
The present invention relates to a device for manufacturing ready-to-use knifing filler by mixing at least two components, in particular a binder component and a hardener component, to form a pasty or liquid mixture.
2. Description of the Related Art
Such devices for mixing at least two components are used in manufacturing knifing filler, for example, wherein a hardener component is mixed with 1-2% of a binder component to generate curable knifing filler. The mixing device has inlet holes for introducing the respective components, through which the components are introduced into the mixing chamber. The components are stored in upstream receptacles such as cartridges or the like, wherein the mixing device is part of an arrangement for providing knifing filler.
DE 203 07 518 U1 discloses such a device for manufacturing ready-to-use knifing filler for spackling surfaces, for example of motor vehicle bodies. The device has two containers situated on a base station, of which one is filled with a binder component, specifically a knifing filler component, and the other is filled with a hardener component. A metering device is used to continuously feed the two components via a respective supply channel to a mixing chamber, in which the components enter into contact with each other. The mixing chamber consists of a section of flexible tubing, gripped on the outside by press rollers that compress the section of tubing while simultaneously actuating it around a longitudinal axis. The resultant friction and adhesion of components to the inner wall of the tubing mixes the components. After the materials being mixed have passed through the section of tubing, they get to an outlet hole provided on the tubing, through which it continuously exits the tubing. The tubing wall consists of airtight plastic, so that the air around the tubing cannot get into the materials being mixed during the mixing process, and get trapped therein in the form of pores or voids.
Known from EP 1 627 690 is an adhesive gun for purposes of application, in particular of a two-component adhesive, which easily enables a broad range of mixing ratios between a relatively viscous adhesive component and a relatively fluid adhesive component in an adhesive gun. This adhesive gun encompasses a first cylindrical container provided with a first plunger for pressing a relatively viscous adhesive component out of a first cylindrical container, a second cylindrical behavior provided with a second plunger for pressing a relatively fluid adhesive component out of the second cylindrical container, a mixing unit into which the first cylindrical container and second cylindrical container empty, wherein the driving means are rated for velocity of the first plunger that exceeds the velocity of the second plunger, wherein the first cylindrical container has a larger inner diameter than the second cylindrical container.
EP 1 570 805 A discloses a device for generating a mixture out of several components, in particular for dental purposes. This device encompasses at least two cartridges, wherein each cartridge contains one component of the mixture comprised of several components and a plunger equipped to press the component out of the cartridge, and a drive unit for the plungers, in which the driving velocity can be set, wherein the drive unit has a stepping motor. At low revolutions per minute, the stepping motor is to provide a higher torque by comparison to known d.c. motors, while it also makes high revolutions per minute available, even if at a comparably low torque, which is sufficient for a rapid advance and retraction of the plungers.
U.S. Pat. No. 6,499,630 B discloses a device for the equally proportionate removal of two or more free-flowing substances from two or more syringes, of which at least one can also be used alone or in conjunction with other syringes, in particular for dental purposes. This device provides that both the syringe bodies and syringe plungers can be rigidly coupled together in the feeding direction via detachable coupling devices. The coupling devices are here designed in such a way that the plungers and/or syringe bodies can be joined in any position relative to each other in the feeding direction. Further, this device provides that the syringe bodies can only be coupled together in a predetermined relative position, while the plunger rods belonging to the plungers can be coupled together in any relative position.
However, practice has shown that the knifing filler mixed with the device occasionally still exhibits inhomogeneities. During application of the knifing filler on the surface of a motor vehicle body, the knifing filler does not cure in locations where no hardener component is present. Eliminating such defects is associated with a relatively high outlay, since the knifing filler must be removed from the body via grinding, whereupon the body must be spackled again. If such defects go unnoticed during a repair, and the body is thereafter painted, it even becomes necessary to paint the spot again. If the mixing device is not operated for an extended period of time, the knifing filler can dry and cake, especially in the end area of the ducting, which renders the device useless. In addition, the ducting is exposed to considerable wear, since significant flexing work is introduced into the tubing during operation of the device. Further, the device is very expensive and space-intensive owing to the press-rollers or rolls.
Another disadvantage has to do with the fact that adding the hardener component cannot be subjected to a visual inspection, so that a uniform supply of hardener component and binder component to the mixing device is not ensured.